Stabilized lubricants



Patented May 1, 1951 2,551,525 STABILIZED LUBRICANTS Robert E. Burk,Wilmington, 051., and Everett Hughes, Cleveland Heights, Ohio, assignorsto' I The' Standard Oil Company, Cleveland, Ohio, a corporation of OhioNo Drawing. ApplicationxNovember 23, 1943, Serial No. 511,472, which isa division of'application Serial No. 424,362, December 24, 1941.

Divided and this application May 19, 1948, Se-

rial No. 28,055

1 Claim.

The present invention relates to lubricants, this application being adivision of our application Serial No. 511,472, filed November 23, 1943,now Patent No. 2,468,031, which is a division of application Serial No.424,362, filed December 24, 1941, now Patent No. 2,346,357, and it hasamong its objects the provision of improved lubrication in hightemperature, such as in internal combustion engines. Other objects andadvantages will appear as the description proceeds.

To the accomplishment of the foregoing and related ends, the invention,then, comprises the features hereinafter fully described, andparticularly pointed out in the claim, the following description settingforth in detail certain illustrative embodiments of the invention, thesebeing indicative, however, of but a few of the various Ways in which theprinciple of the invention may be employed.

The lubricant base may be a usual lubricating oil of viscosity desiredin view of particular duty contemplated, or for instance 45 to 200 sec.S. U. at 210 F. We have found that salts of metals having oxidationactivity or which are oxidation catalysts not particularly at crankcasetemperature but at higher temperature promote diminution of carbonaceousdeposits outstandingly, and in combination with what we term anantioxidant give results much better than the total of the respectiveagents alone, anti-oxidant here having a meaning not as with gasolinebut as an inhibitor for metal catalysts such as iron, copper, or lead.It is particularly remarkable that an agent of oxidizing character andwhose activity tends primarily to be antagonistic to anti-oxidant actionshould work to these ends. The salts of metals constituting theoxidation catalysts comprise: naphthenates; salts of acid radicals suchas of tall oil or sulphurized tall oil; acids derived from the oxidationof petroleum fractions or polymers; xanthic, i. e. acids of the type :5ROCSH in which R is alkyl, aryl, alkaryl and sufficient to solubilizethe metal compound; medium molecular weight fatty acids chosen so thatthe resulting salt will have 15-30 carbon atoms; acids derived fromsaponified wool fat (degras) with or without the alcohol, and the woolfat may be sulphurized, e. g. with P2S5, before or after hydrolysis; andfor conciseness such acids are hereinafter designated organic acids oflow volatility, the stated salts of which promote diminution ofcarbonaceous deposits. The naphthenates may also be chlorinated orhalogenated, and in some cases sulphurized. The metals above referred toare chromium, also vanadium, manganese and molybdenum. In general, to 2per cent, or more, up to 3 per cent, of the metal compound may be used.The metal salts are used with the said anti-oxidant agents. These agentscomprise sulphur-containing compounds, as P285 treated degras, P285treated polyolefins, and P255 treated distilled cashew nut shell oil.The reaction between cashew nut shell oil and phosphorus sulphide isdisclosed in the patent to Hughes No. 2,411,160, in the third paragraphthereof. Up to 3 per cent, preferably 4 to 2 per cent of such agentadditive to the metal compounds may be employed.

As an example: a lubricant is made up of S. A. E. 20 lubricating oil and0.5 per cent of chromium naphthenate and 1.5 per cent of the reactionproduct of P2S5 on degras.

As another example: A lubricant is made up with a similar oil and 0.5per cent of chromium oil- 0.5% Or 9 312123 5,3

PQSI degras Carbon Residue at- 525 F F F 750 F A- A-- Detergency:

Carbon suspension O- A Ox dation test A- A Oxidation Test:

Deterioration A- A+ Corrosiveness A- 11-]- The carbon residue isdetermined by exposing a 2.5 g. sample of the lubricant in a mm.diameter Petri glass dish in an electric furnace for 16 hours at 525 F.,followed by 6 hours at 750 F. The carbon suspension is determined bysuspending 5 per cent by volume of carbon in the lubricant, and a cc.sample of the suspension in a 100 cc. graduate is set in an oven at 200F., and the number of cc. of clear oil is measured 3 at intervals. Theoxidation and lacquer is .determined by exposing the lubricant in thepresence of metals, iron and copper, at a temperature of'3'10' F. for65mins byblowin'gair through at the rate of '30 liters per hour.

Other modes of applying the principle of the invention may be employed,change being made as regards the detail described, providedthe featuresstated in the following claim, or the equivalent of such, be employed.

We therefore particularly point out and distinctly claim as ourinvention:

A lubricant promoting combustion of deposits in the combustion zone ofinternal combustion engines and producing high stability-in the crank1'6 2,301,795

4 case, which comprises a lubricating oil and A; to 3 per cent of thereaction product of phosphorus sulphide on cashew nut shell oil, and to3 per cent of chromium naphthenate.

ROBERT E. BURK. EVERETT C. HUGHES.

10 file of'this patent:

UNITED STATES PATENTS Number Name Date 2,169,634 Cantrell et al. Aug.15, 1939 Proell Nov. 10, 1942

